Move indent from `t/sizes` to `t/test`.

Moved the four character indent from `t/sizes` to `t/test`. When I run
`t/sizes` for commit messages, I don't to have to dedent.

File                             Raw         Min         Zip     Min/Zip
index.js                 28950/28.27  9293/09.08  7339/07.17  3557/03.47